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=20
First time user, thank you for any suggestion:
=20
=20
    We have a motor controller built here: there are two turn-on and fwd/=
rvs press buttons on a case top, which connects to the PCB inside via som=
e signal cable. The input to the board is 110V AC, since there is no eart=
h ground presents, the high and low input voltage could float to higher t=
han 110.
=20
    The problem is: if the buttons are somehow shorted to earth ground at=
 the case top (even if we have built almost perfect insulation on the cha=
ssis), there will be about 40mA comes from the switch button, goes throug=
h human body, which kills. Is there anything we can do to this situation?=
=20
=20
    I'm just a junior engineer, so it might seems a stupid question to yo=
u guys, but thank you very much for any help.
=20
=20
=20
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MSN=CA=A5=B5=AE=C0=F1=CE=EF=BB=F0=C8=C8=B5=C7=B3=A1=A3=AC=C3=E2=B7=D1=B7=A2=
=B7=C5=D6=D0=A3=AC=BF=EC=C0=B4=C1=EC=C8=A1=B0=C9=A3=A1
http://im.live.cn/emoticons/?ID=3D18
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